1. Field of the Invention
This invention relates to an electrical component pick and place machine having one or more carriages that pick multiple electronic components, transport the components to a substrate, and simultaneously place multiple components on the surface of the substrate in a single step.
In this discussion, and in the summary, description, and claims that follow, the terms "substrate" and "components" will be used in a broad sense. In this regard, a substrate will be a workpiece on which "components" are placed. Relatedly, a substrate may signify, without limitation, a single printed circuit board (PCB), a panel of PCB's, a ceramic substrate, an additive board, or a flex circuit, or any other equivalent structure. A component is a part that is placed on a substrate, and may be embodied in an electronic device, component, stud, or heat sink, or any equivalent thing.
Moreover, the terms "placement" and "mounting" are synonymous, when used to signify putting components on substrates in particular positions.
2. Discussion of the Related Art
A surface mount placement system with reciprocating turrets is disclosed and claimed in U.S. Pat. No. 5,323,528. The '528 patent is commonly owned with this patent application and is incorporated herein in its entirety by this reference.
The surface mount placement system of the '528 patent describes a surface mount device (SMD) placement system that is used to assemble printed circuit boards (PCB) with surface mount electrical components. The surface mount placement system (SMPS) of the '528 patent includes a table that carries a PCB along a Y axis to a component mounting zone. An elongated rail structure extending parallel to an X axis, and intersecting the Y axis at the component mounting zone, carries left and right turrets that are moveable independently along the X axis, supported by the rail structure. The left and right turrets operate reciprocally, one receiving components from multiple feeder stations while the other places components on a PCB at the component mounting zone. Because the turrets move on the X axis while the PCB moves on the Y axis during placement, the system of the '528 is referred to as a split axis system. A plurality of component pick-up quills is mounted in each turret. Each turret is rotatable about a vertical central axis and each quill is moveable selectibly only along a Z axis that is parallel to the vertical central axis of a turret. In the '528 SMPS, each quill is constrained from rotational movement with respect to the turrets. The quills are constructed to pick up selected electronic components ("pick") from a selected associated component-dispensing mechanism and to mount selected ones of the components at desired locations ("place") on a PCB in the component mounting zone. The turrets are operated so that the quills of either turret are capable of picking components while the quills in the other turret are placing components.
The SMPS of the '528 patent places electronic components very accurately. Further, the rotating turrets of the '528 SMPS are flexible and versatile, handling a large variety of component shapes and sizes with mechanisms that are simple.
Nevertheless, industry demand for increased productivity continues to generate a need for higher speeds of operation. There is an upper limit to the throughput of a SMPS which places a single component in a single place step. Furthermore, there is a need for versatility in placement in that PCBs may need to be populated not in individuated units, but in a panelized unit that may include two or more individual PCBs. In such cases, redundant placements of identical components in identical positions on two or more PCBs in a single panelized unit may be necessary or desirable. Instead of making the placements singly in successive steps, it would be convenient, and faster, to make two or more placements simultaneously, in a single step. Still further, it would be desirable to be able to place multiple components on a single PCB at different locations in a single place step. It should therefore be clear that an accurate and reliable SMPS that places multiple elements in a single place step would constitute a significant advance in the art.